There are two sizes of the spool in the manual shut-off valve

Full spool, he is the most commonly used and related to the area of ​​the seat ring, the size of the area of ​​the cut-off valve by the maximum flow. On the other hand, when the throttle valve compared to the size of the valve rated flow is low, the reduced diameter spool. If spool must be in smaller increments case closed throttle seat, but it is difficult to obtain a hand actuator. The first way is to use the small diameter of the valve seat and a cock to match, he called reduced diameter spool.

solenoid valve actuator

The bonnet is an important element of the top of the workpiece, as pressure parts for the valve body to provide a cap or cover. Once it is installed on the valve body, the valve cap or valve gasket seal. He also used the stuffing box seal spool rod stuffing box includes a series of packing rings, gland or guide cover. Filler spacer sleeve and anti-extrusion ring to prevent the leakage of a small amount of process fluid to the atmosphere. Installed above the stuffing box gland flange bolts and the top of the bonnet connection. When the gland flange bolts are tightened, the packing is compressed and sealed stem and bonnet hole.

3 way air valve